FIG. 6.

Accumulation of p53 protein in normal (Mori) and AT (AT2KY) fibroblasts induced by treatment with a proteasome inhibitor. Normal (lane 2) and AT (lane 5) fibroblasts were treated with lactacystin (50 μM) for 3 h. Some cells were treated with lactacystin (50 μM) for another 3 h in the presence of cycloheximide (20 μM) (lanes 3 and 6). p53 protein levels were determined by Western blotting with anti-p53 monoclonal antibody PAb 1801. Lanes 1 and 4 are extracts prepared from untreated cells. p53 bands are indicated with an arrow.